Rotary pump



Get. 20, 193L w. w. DAVIDSON 1,828,245

ROTARY PUMP Filed Dec. 8. 1930 4 Sheets-Sheet l Oct. 20, 1931. w, w DAVIDSON 1,828,245

ROTARY PUMP Filed Dec. 8. 1930 4 Sheets-Sheet 2 OC- 20, 1931 w. w. DAVIDSON 1,828,245

ROTARY PUMP lFiled Dec. 8. 1930 4 Sheets-Sheet 3 Oct. 20, 1931. w. w. DAVIDSON 1,828,245

ROTARY PUMP Filed Dec. 8. 1930 4 Sheets-Sheet 4 Patented ct. 20, 1931 UNITED STATES WILLIAM WARD DAVIDSON, OF EVANSTGN, ILLINOIS ROTARY PUMP Application led December 8, 1930. Serial No. 50,892.

This invention relates to rotary pumps.

Objects of the invention are to provide a rotary pump which will be simple in construction, relatively inexpensive to manufacture, positive and highly efficient in operation, and in which actuated parts of the y pump, including the vanes, will be subjected to relatively slight frictional resistance in operation, thereby reducing wear and obviating the necessity for renewing worn parts at comparatively short intervals in order to maintain eliicient performance of the pump.

To eifect the objects thereof, a pump embodying my invention and improvements comprises the various features, combinations of features and details of'construction hereinafter described and claimed.

In the accompanying drawings, in which the invention is fully illustrated,

Figure 1 is a top plan view of a pump embodying my invention and improvement, adapted to be driven by a motor directly connected to a pump member.

Figures 2 'and 3 are, respectively, sectional views on the line 2-2 of F ig. 1, and in a.

plane degrees from that of Fig. 2, the rotor being turned 45 degrees from its position shown in Fig. 2.

Figures 4 and 5 are sectional views both taken on the line 4 4 of Fig. 1, but showing the parts of the pump in different positions to illustrate the action of the pump in operation.

Figure 6 is a view substantially similar to Fig. 4. showing a slightly modified construction.

Figure 7 is a side view, partly in section, showlng my invention embodied, in a pump driven from a separate source of power.

Figure 8 is a sectional end view on the line 8-8 of Figure 7.

Figure 9 is a perspective vi'ew of the shaft of the pump shown in Figs. 7 and 8; and

Figures 10 and 11 are enlarged fragmentary detail views.

Describing the invention with particular reference to thel drawings and referring, in the first instance, to Figs. 1 to 5, my improved pump comprises what, for purposes of con venient reference, will be called a cylinder and a rotor, designated, respectively, as a whole A and B, rotatably mounted, "in eccentric relation. on a fixed shaft 1.

The cylinder A consists of an annular ring 2, opposite ends of which are closed by heads or disks 3 and 4, which, foreconomy of manufacture, preferably form separate parts and are removably secured to said annular ring by screws or other suitable means. Formed on said heads or disks, respectively, are bearing hubs or bosses 5 and 6.

The rotor B is cylindrical, its diameter being less than the diameter of the bore of the cylinder A, its axial length being 'propor-l tioned to fit between the inner sides of the heads or disks 3 and 4 with only suflicient clearance to permit the free turning movement of said cylinder and rotor in operation,

'relative to each other.

Ifn operation, the cylinder A and rotor B are rotatably mounted in a suitableframe comprisingka base 7, formed on which are spaced journal boxes or pedestals 8 and 9, one and, if desired, both of which form separate parts detachably secured to the base 7. 75 As shown, one end of the shaft 1 is pinned or l otherwise ixedly secured in a bearing formed to receivelit in oneof the journal boxes-as shown, in the ournal box S-the unattached end of said shaft overhanging, asshown.

At its end adjacent the attached end of the shaft 1, the cylinder A is rotatably mounted by means of a bearing formed in the boss or hub 5, which engages a bearing on the overhanging portion of said shaft, as shown at 10. At its opposite end, said cylinder is rotatably mounted by means of a bearing formed on the boss or hub 6, which is fitted to turn freely in a bearing formed in the journal box or pedestal 9, said bearing preferablyl 9 having a removable cap, as shown in Fig. 1.

In what I now consider the preferable construction, the axis ofrotation of the cylinder A is substantially coincident with the axis of the attached end of the shaft 1.

The rotor B is rotatably mounted on a bearing formed on the overhanging portion of the shaft 1 exposed within the bore of the cylinder A, as best shown at 11, Figs. 2, 5 and 1 6, said bearing being eccentric to the bearing the opposite edges of which 10 for said cylinder, the relation being such, preferably, that the perimeter of said 'rotor Will be tangent to the bore of the cylinder, with only sufficient clearance to permit relative turning movement of their adjacent surfaces without friction.

iVith the described construction, it is obvious that an air chamber 12 will be formed between the opposed cylindrical surfaces of the bore of the cylinder and the perimeter of the rotor. As presently described also, the cylinder A and rotor B are operatively connected so that they will rotate together, whereby, said air chamber 12 will move progressively around the shaft 1.

In accordance with my invention, also, a lurality of vanes-as shown four-extend tween the cylinder A and rotor B, in such relation that they will divide the chamber 12 into a plurality of separate compartments, said vanes comprising an impelling vane 13, having fiat parallel sides, which may be secured either to said cylinder or rotor at one edge and which is slidably fitted to a radial slot 14 formed in the other, and other vanes c, an edge of each of which is pivotally conneeted either to said cylinder or rotor and have both pivotal and sliding connection with the other thereof, said pivot connections being arranged to provide for necessary pivotal movie` ment of said vanes c in operation, due to the eccentric mounting of the cylinder and rotor.

As shown, the vane 13 is secured to the cylinder A and the slot 14 is formed in the rotor B, but this arrangement may be reversed within the scope and contemplation of my relatively invention, if desired.

As shown, also, each of the vanes c comprises a cylindrical portion 15 formed at one edge thereof, fitted to turn freely in an opensided bearing-16 formed either in said cylinder or rotor, and a parallel-side portion 17 slidably fitted to a slot 18 formed in a cylindrical member 19 fitted to turn freely in an o ,n-sided bearing 20 formed in the pump mem r other than that with which the pivot 15 engages, said pivot members 19 being made sufficiently large to provide aslot 18 of proper depth to rmit designed relative movement of the cyllnder and rotor in operation.

As shown, the impelling vane 13 is made thick, so that it will be strong and rigid and willl sustain the entire duty of impelling the pump member to which it is slidably fitted. Thus, the only stresses sustained by the vanes c will be those developed by the air pressure produced in the operation of the pump. Obviously, these stresses will be ve small, thus permitting said vanes c to be made thin and very light.

As shown, the open sides of the bearings 16 and 20 are cut away, to provide for necessary pivotal movement of the vanes c in operation.

As shown, the pivot bearings 16 aYe formed in the c linder and the bearings 20 in the rotor. owever, as with the impelling vane 13, the arrangement shown may be reversed without departing from the invention.

The admission and discharge ofI air from the air chamber 12 of the pump is effected by means of passageways 21 formed in and which extend radially through the rotor, and

.which are arranged between adjacent vanes of the pump, their outer and inner sides being in open communication with the interior of the cylinder and the rotor bearing, respectively, and their inner open sides being brought successively into communication with cut-away portions 22, 22', on opposite sides of the shaft 1, as said rotor rotates in operation, said cut-away por` ions of the shaft being positioned at about the longitudinal center of the rotor bearing 11.

, Communicating with the recesses formed by the cut-away portions 22, 22', of the shaft 1 are fluid 'supply and discharge passageways 23, 23', formed in the attached end of the shaft 1, the ends of said passageways being open to provide for the admission and discharge of air or other fiuid to and from the vrecesses 22, 22', and thus through the passageways or ports 21 in the rotor, to and from the air chamber 12 of the pump.

Assuming that the pump is rotating in the direction indicated by the arrows, Figs. 4 and 5, the passageway 23 and connections will form the fluid admission passageway, and 23 and connections the fluid discharge passageway.

The pump shown in Figs. 1 to 5 of the drawings is designed and adapted to be driven by coupling the bearing hub or boss 6 thereof directly to the armature shaft of an electric motor or other source of power, not shown, all as indicated in Fig. 2, in

'which 24 indicates the armature shaft and 25 the coupling.

As a modification of the pump shown in Figs. 1 to 5, I contemplate a construction in which the impelling vane 13 has no function except to drive the pump member with which it has sliding enga ment, said impelling vane being provide withholes adjacent its pivoted edge, permitting air to pass freely from one side to the other thereof, when exposed inthe fluid chamber of the pump.

This dnstruction is shown in Figure 6 of the drawings, in which the pump is shown as having three vanes c arranged at angles of substantially 120 degrees to each other` the impelling member -13 being positioned between two thereof and being provided, adjacent its attached edge, with holes 26, see

'Figs 6 and 11, whereby an equal pressure vention and improvements as embodied in a well known form or type of pump which is extensively used commercially for producing either suction, fluid pressure, or both, an

which illustrates the embodiment of my invention as applied to a pump driven by belt connection applied to the rotatable cylinder from any suitable source of power, not shown.

Asregards its novel features, the construction of the pump conforms to the construction of the pump shown in Figs. 1 to 5 and heretofore described, and the same description will apply equally thereto, and corresponding parts are, therefore, designated by the same reference characters in all figures.

As shown, the only feature of difference between the two forms of pumps is that while the pump shown in Figs. 1 to 6 is directly connected with a driving motor, that shown in Figs. 7 and 8 is driven from a separate source of power, not shown, by means of a belt 27, which engages al V-groove 28 formed directly on the outside of the cylinder of the pump.

Also, the pump shaft l, instead of overhanging, is supported at both end in bearings formed in the bearing standards 8 and 9, being pinned or otherwise secured against rotation to one thereof.

Also, due to the fact that both ends of the shaft 1 are unobstructed, the passageways 23, 23', instead of being formed in the same end of the shaft, are formed in opposite ends thereof, as shown in Fig. 9, both journal bearings being provided With fittings adapted for making pipe or hose connections to said passageways, respectively. However, there is nothing to prevent both of the passageways 23, 23 beingr made inthe same end of the shaft, if desired.

As shown, also, the base 7 on which the bearing standards Sand 9 are formed is slidably mounted so as to be adjustable towards and from the motor, to provide for adjusting the tension of the driving belt, in a usual manner.

The pump shown in Figs. 7, 8 and 9 is rel-` speed. Said pump is designed for use where a large volume of fluid is to be delivered.

\ While, as regards their features of novelty,

the structural details of both pumps are substantially the same, the larger pump is here shown for the purpose of illustrating the relativelyV great eccentricity of the cylinder and rotor which can be obtained with a prac"- `tical Working engagement of the impelling member 13 with the slot 14, thus insuring relatively a very large air or fluid chamber 12 and a capacity for handling a correspondingly large volume of air or other fluid.

To prevent air or other fluid being trapped inthe bottoms of the slots 14 in operation, all

pump vanes, and theimpelling member 13,

are provided with slots 29 which connect the bottom of said slots with the air space 12, see particularly Figs. 10 and 11.

I claim:

1. In a rotary pump, the combination of a cylinder, heads which close the ends of said cylinder provided with bea1ings concentric with the bore of the cylinder, means for rotatably mounting said cylinder comprising a frame, a fixed shaft thereon which comprises an eccentric portion which is exposed withinand discharge connections to and from the air chambers of the pump, comprising re;l

cesses formed in opposite sides of the eccentric portion of the pump shaft, passageways in said shaft which are in open communication with said recesses, respectively, and ports formed in the rotor arranged for connecting the air chambers of the pump defined by the pump va-nes with the recesses in the fixed pump shaft in continuous succession during operation.

2. In a rotary pump, the combination of a cylinder, heads which close the-ends of said cylinder provided with bearings concentric with the bore of the cylinder, means for rotatably mounting said cylinder com rising a frame, a fixed shaft thereon whic comprises an eccentric portion which is exposed Within said cylinder, a rotor rotatably mounted on theeccentric portion ofsaid shaft in tangential relation to the bore of the cylinder, a plurality of vanes connecting said cylinder and rotor comprising an impelling vane pivoted to the cylinder and slidably fitted to a slot formed in the rotor whereby said cylinder and rotor will rotate together, and the other vanes being pivoted to the pump cylinder and having pivotal and slidable engagement with the rotor, said pump being provided With`r air supply and discharge connections to and from the air` chambers of the pump, comprising recesses formed in opposite sides of the eccentric portion of the pump shaft, passageways in said fixed .shaft which are in communication with said recesses, respectively, and ports formed in the rotor arranged for connecting the air chambers of the pump defined by the pump vanes with the recesses in the pump shaft in continuous succession during operation.

3. A rotary pump `ik specified in claim l, in which the cylinder 1s rotatably mounted at one end by means of a hub formed thereon fitted to rotate in a bearing in the pump frame whereb said cylinder may be directly connected Wit the shaft of a driving motor.

4. A rotary pump as specified in claim 1, in which both ends of the cylinder are rota'tably mounted on the fixed shaft and rotation may be imparted to the pump cylinder by differential driving connection thereof with the shaft of a driving motor.

In witness that I claim the foregoing as my invention I ax my signature this 6th day of December, 1930.

WILLIAM WARD DAVIDSON. 

